1. Field of the Invention
The present invention relates to a rotor structure. Priority is claimed on Japanese Patent Application No. 2011-059706 filed on Mar. 17, 2011 the entire content of which is incorporated herein by reference.
2. Description of Related Art
As is well known, in a rotary machine, typical examples of which are a compressor and a turbine, a rotor having a plurality of moving blades arrayed on an outer circumference of a rotation shaft body in a circumferential direction is used.
For example, in Japanese Published Unexamined Utility Model Application, First Publication No. Hei-3-25801, a structure such that many moving blades are embedded in a blade groove bored on an outer circumference in a circumferential direction of a rotor of a rotary machine is adapted. In Japanese Published Unexamined Utility Model Application, First Publication No. Hei-3-25801, a blade fixing piece is fitted between the blade basements of adjacent two moving blades. Then, in Patent Document 1, a bolt is screwed into a threaded hole formed at the center in a radial direction of the blade fixing piece. On the other hand, a round hole is bored on a bottom face of the blade groove, and a lower end of the bolt is fitted into the round hole, thereby restricting displacement of the moving blades in a circumferential direction.
However, in the conventional technology, an inner wall part of the round hole is a structurally discontinuous part. Thus, stress concentrates in the vicinity of the round hole and cracks may occur.